Nelson Historical Society Journal, Volume 6, Issue 5, 2002

The Rocks Road Seawall

Following a visit to Nelson exactly 25 years ago this July, I wrote to the then Nelson Evening Mail expressing my enthusiasm for the seawall between Tahunanui and Nelson as an excellent example of seaside civil engineering. At that time I knew virtually nothing about its origins, except that it was said to have been built by prisoners. Together with an illustrated article about its history prepared by Mail staff, the newspaper published my letter, which I had ended by saying that, in my opinion, the wall was undoubtedly of a quality which warranted recognition as a significant historic structure. But to no effect. I am now reiterating that long-held opinion, on this occasion reinforced with evidence to support and strengthen it.

Origins

'In 1891…the City Council, the County Council and the Richmond Borough Council set up a Road Round the Rocks Committee and the work was begun'.

'When the idea of the Rocks Road was mooted Francis Richmond agreed to give some land along the front of the Cliffs so that the road could be made. The Road Committee built its wall along the rocks and then filled in the roadway with material dug from the Cliffs'.

CB Brereton.

'Any fool can make a straight road, it takes a good man to put the curves in'. Sam Jickell, when asked why there were so many curves in his 1885 design for the roadway and seawall.

In the mid 1870s Nelson City Councillor Thomas Harley proposed what he called 'a half-tide roadway' around the rocky shoreline between Nelson Haven and Tahunanui. It was not until the early 1880s that Nelson City and Waimea County obtained Government subsidy approval for a roadway.

Born in Stockton on Tees, Samuel Jickell Amice was 29 when he completed his 1885 design for the proposed road and seawall. Educated and trained in Europe, he was appointed Nelson City Engineer after only a few years in New Zealand and following a period of private practice here. His other works for the Council included the replacement Saltwater Bridge, the City Abattoirs and a fulsome report on the question of the city's water supply.

Jickell, the founder and first President of the Institute of Local Government Engineers, became City Surveyor in 1891 and resigned in 1901, becoming Petone Borough Engineer, and then held the same position in Palmerston North from 1904 to 1919. He was responsible for a large number of projects in that region, most noticeably the many reinforced concrete improvements to roadway structures and bridges through the Manawatu Gorge.

Six years after his first Rocks Road proposals, at which time there was still only a precarious, occasionally wave-swept walkway along the coast between the town and the beach, cost-sharing arrangements between Nelson City, Waimea County, Richmond Borough, and the Government were finalised. Nelson Mayor, Francis Trask, later a Member of Parliament, is said to have been much involved in advancing the project.

Although Sam Jickell had indicated the cost would be about £8,000 in 1891, the task, not surprisingly given its high seas and tall cliffs constraints, proved more difficult and expensive than expected and the final cost was almost £12,000.

After a Nelson City ratepayers' poll returning 38 against and 863 in favour of the project, the special-purpose committee set about arranging for work to begin on site in early 1892. No tenders were received when the Waimea County Council advertised for the supply of stone blocks and, though they were said to be more expensive, it was reluctantly agreed to build the seawall with blocks of concrete.

19th Century Construction

More than one account of the building of the wall has it that granite blocks were used in its construction and Geoffrey Toynbee Be, Mnzie, who was City Engineer when later alterations were carried out, indicated to me that granite may have been used. Inspection of parts of the wall at the foot of Richardson Street and near the much later Connolly Quay, however, where some of the original blockwork can still be seen, reveals surfaces of concrete and not granite.

This evidence is confirmed in a construction photograph from the Tyree Collection taken in 1894, which clearly shows large, rectangular, rebated, precast concrete blockwork both in the wall and in stacks nearby. Interestingly, however, a number of smaller, square, smooth-faced blocks can be seen lying on the ground near the wall, and these could well be of granite.

Cecil Nash, later known as a pioneer of the Nelson tobacco industry, but in the late 1890s a Nelson City Council employee, is said to have been the maker of the concrete blocks, which were cast near Albion Wharf and taken to the site by sea.

Waimea County Council was responsible to the Committee for work up to its boundary at Magazine Point, so named for the cache of explosives kept in a cave there. Numerous anecdotes refer to the convict labour used by the City Council to build the eastern section of the wall. According to CB Brereton 'each morning…a party of 20 left the gaol in Shelbourne Street and marched…to Rocks Road…they wore ringed jerseys of black and yellow and were known to the boys as Sam Jickell's football team'. He goes on to tell several stories about the prisoners involved in the work.

In this regard, Geoffrey Toynbee recalls his impression that the eastern, more sheltered and thus more vertical part of the wall was prisoner-built in granite. It was of better quality construction than was the case with the more exposed and thus more sloping western section. This recollection is supported by the 60 metre length of early seawall still visible between the old city powerhouse and the sea rescue launching ramp on Wakefield Quay. Built with granite blocks in regular courses, it appears to be a remnant of the easternmost end of the 19th century construction which resorted to concrete blocks further west.

Raising funds to meet rising costs brought about by construction difficulties meant progress was slow, with the prisoners being criticised for being the slowest. It was a time of great economic hardship in the region. By 1895, however, though much filling was still to be done where the new wall had been built well out from the cliff face, a rough, narrow roadway was available to those who were prepared to use it at their own risk.

That the hazards were real, both from wave action and rockfalls, is well illustrated by the provision of looped ropes and lifebuoys along the seawall and by the use of convict labour. Later on, explosives were used to reduce the overhang of the cliffs along part of the road. The whole length had been surfaced with gravel by late 1897. In the same year repairs were carried out to damaged areas along the Waimea County section of the wall face, where sea action was already proving to be more severe than was the case in the lee of Haulashore Island further east.

The handsome and substantial stanchions and chains along the top of the western section of the wall, money for which was donated by pioneer Nelson settler John Tinline and his English friend James Tytler, were in place by early 1898, a full year before the road was officially opened for use.

At the Basin Reserve, in a ceremony complete with a triumphal arch at the boundary between the City and County territories, bright flowers, flags and music by the Garrison Band, Prime Minister Richard Seddon formally opened the roadway on 3 February 1899. The official party, which included the Mayors of Nelson and Richmond, members of the Nelson City, Waimea County and Richmond Borough Councils, and Mr Jickell, were all seated on a platform behind what was known as the Record Reign Fountain. This, presumably, was a now lost 1887 memorial to Victoria's 50 years as queen.

Just a week later the occupants of a passing trap were severely shaken when a large rock fell on it while on their way from Richmond to the port. Sam Jickell was immediately instructed to have loose rock removed from the cliff faces above the new roadway. The signposted hazard warning to those using the road was clearly no idle one.

Responsibility for the newly-built road and seawall was taken over by the Government in 1903 under the provisions of the Public Works Act. In 1913, following several vehicle accidents along the outer edge of the still unfenced section, the 1898 post and chain protection was extended along Wakefield Quay through a bequest to the City for the purpose from Thomas Cawthron.

20th Century Alterations

In late 2001, because of its relationship to the problems being experienced at the eastern end of Tahunanui Beach, I found myself looking again at the seawall, this time much more closely than I had in 1977. Consultants to the NCC had referred, in their 2001 report on the state of the beach, to 'the concrete, close to vertical face, seawall retaining Rocks Road' and had continued by saying that 'Waves incident on the wall reflect off it with negligible energy loss'.

Standing on the beach looking eastwards to the wall, it was clear to me that it had been specifically designed to absorb wave action, and this prompted me to look into how it came to be built that way. In doing so I came to appreciate the way its newer western section had been deliberately arranged to absorb wave action and, by this means, greatly reduce the storm wave effects. These, I learnt, had on occasions made the original roadway near impassable when high tide and high onshore wind conditions coincided.

Given its obvious sophistication and knowing something of the complexity of the design task – it is by no means a plain straightforward seawall – I would not have been surprised to discover that experienced, international civil engineering consultants had been involved. My initial enquires led me to two previous City Engineers, Mac Crampton and Geoffrey Toynbee, both of whom confirmed that what could now be seen was, in fact, a combination of 19th and 20th century construction. The later work had been designed and supervised by Nelson City Council staff during the period when Charles Kidson was City Engineer.

In September 1958 the City Engineer advised his Council that, with Government financial assistance obtained largely through the advocacy of Nelson MP Stan Whitehead, improvements to the Sam Jickell-designed roadway and seawall were to be carried out in three stages. By then, work on the first stage, from Tahunanui Beach to Magazine Point, was already nearing completion.

The second stage was to be from Richardson Street to the Anchor Foundry and the third would be the formation of a 40ft dual carriageway from Port Nelson to Anzac Park. The planned overall project completion date was 1962. The last stage was eventually completed in late 1964, to the delight of the local Automobile Association, which described it as 'an excellent entrance to the city…as fine as any in New Zealand'.

This staged work programme explains the present three-part appearance of the face of the seawall. The primary purpose of the alterations was to raise and widen the roadway in order to provide greater protection from the sea for those using Rocks Road. The considerable length of wall left unaltered between the first and second stages lay within the zone sheltered from heavy seas by Haulashore Island and by the rocky shore in front of it, and thus did not need such alteration.

This means that the near-vertical face of the central third of the Rocks Road seawall reveals the original 19th century construction. The raking, ribbed and facetted western third was built against the face of the old wall in 1958/1959. The raking eastern third, much like the western section, but with more substantial ribs and no facets, was also built against the face of the old wall and was scheduled for completion in late 1962.

The need for a taller and more durable seawall arose not only because of the overtopping which occurred in adverse weather, but also because of the effects of sea action on the old one. This was washing away the jointing material in its concrete block construction and seriously eroding the fill under the roadway behind it. The still-visible part of the old wall face was given a sprayed-on plaster coating in order to protect it, but it is of concern to note that this plaster has been damaged in places.

The solution conceived by City Council engineering staff, led by Geoffrey Toynbee, in the late 1950s consisted of a new, relatively light-weight wall founded on the underlying rock base. It was designed to lie at an angle, braced against the face of the earlier one and supported in places by the sloping rock outcrops left exposed at the foot of the existing wall. This technique also enabled the engineers to accommodate a bulge in the old wall caused by an earlier slump in the cliff face behind it.

The profile and structural details of the western and eastern sections of the new wall differed along their length. These differences depended on the state of the adjoining existing wall, its proximity to Tahuna Beach and the fetch, or degree to which parts of the wall were exposed to distant sources of wave action. At the eastern end of the wall the latter was considerably less, because of the protection provided by the Boulder Bank and Haulashore Island. Another influence on the design was the existence of natural rock outcrops in front of the wall in some places.

The arrangement arrived at in order to absorb wave action consisted of a reinforced concrete wall with an outer raking face at about 450 degree slope, a facetted vertical central section and an outward-projecting top profile at roadway level. The purpose of the outer slope was to reduce the initial wave forces, while that of the facetted section was to deflect downward the waves which rose above the sloping face. The purpose of the top section, built considerably higher than the old wall to reduce overtopping onto the new higher roadway, was to turn back those waves which reached it.

In addition to the effect of the new wall's profile on seas which arrive more or less at right angles to it, the prominent projecting concrete ribs, which stiffen its relatively thin concrete surfaces, also serve to modify wave action in its vicinity. They do this by deflecting outward those waves which meet it obliquely instead of straight-on. The deflection effect also assists in reducing the wave energy which eventually reaches the beach. This is because the most frequent wind direction produces waves which strike the wall from an angle directed towards the beach at its western end and thus travel westward along it.

This was the intention of its designers who, in addition to thoroughly understanding its function as a road-edge structure, were also well aware of the sea-state relationship between the seawall and the adjoining beach. A further indication of their recognition of this relationship shows in the purpose of the additional length of unribbed, unfacetted, plain seawall profile. This was built westward, beyond the water's edge and deep into the dunes, to provide for what they knew would be the sand's inevitable advance and recession as natural forces acted on it over the years.

On the landward side there were two significant design factors. The first was the distance from the new wall to the near edge of the reconstructed roadway proper. In places, the presence and width of the new footpath meant the road traffic loads on the wall were more distant, and thus less severe, than elsewhere. The second factor was the need to provide for page 13the increased wall loads at that part of the old wall where bulging had occurred due to slumping of the Tahunanui hillside.

To my surprise, given the numerous examples elsewhere of seawalls with upper sections continued a metre or so above the level of the adjoining roadway in order to protect passing vehicles and pedestrians from stormy seas, the structure of the new Rocks Road wall was not extended above footpath level. This decision, perhaps made as a cost-saving measure, was to have a profound effect on the appearance of the wall from seaward, from the beach, and when passing by on foot or in a vehicle.

Each of these thoughtfully arranged, sequential wall profiles employed by the engineers are, on their own, not unusual in seawall design, and one or another of them can be seen elsewhere in New Zealand. The Wellington Harbour region has examples of each one, for instance in Oriental Bay, Lyall Bay and Kio Bay. The Rocks Road combination of all four – sloping face, facetted vertical section, projecting top, and vertically ribbed surfaces – is rare indeed however, and I have not seen it anywhere else on our coasts.

Two further qualities make the Rocks Road seawall of special significance in aesthetic terms. One is the considerable visual variety achieved in these interacting, sea-deflecting shapes as they meet the differing circumstances occurring along the outer face of the sinuous curves of Sam Jickell's original wall. The other is the sturdy post and chain fence which, strung out along its top, contributes an impression of filigreed curvature to the complex forms already present in the sinuous concrete wall itself.

Many handsome seawalls go largely unnoticed by passers-by on the roadways and footpaths they support and protect, usually because the wall is continued up above road level, thus blocking views of its outer faces. Here, however, as a result of this local design decision, the whole of the ribbed, raking, winding, seaward surfaces of the Rocks Road wall is clearly visible between and over the posts and chains to all who travel to and from the city.

Later still, in about 1975 it seems, apparently because the height of the old central section was found to be inadequate in heavy sea conditions, a length of the outside edge of the adjoining roadway surface was raised, though the adjoining footpath was left at its existing level. At this time also, a plaster protective coating was applied to the face of the 19th century wall to prevent further erosion of the blockwork joints.

In my 1977 article, impressed by its appearance but largely ignorant of its origins, I described this seawall as 'a priceless visual asset to Nelson' and went on to say 'I have not seen any quite like it. Its ribbed raking massive elegance is combined with considerable variety in its curvature, cast iron and chain balustrades, steps, and plain vertical profile at rock outcrops…all providing an object lesson in nautical engineering'.

To my delight, at the end of the 1970s refurbishment work was carried out on the posts and chains, some by then almost 80 years old and showing considerable deterioration. Later still, in the early 1980s, further repair and protection work was carried out on the old wall face where it was still exposed to the action of the sea.

In Conclusion

The more I have found out about the wall's origins, design, development and purposes, the more convinced I have become that, as I also said in 1977, 'It is a truly great wall, as grand as any seawall in New Zealand. It is as important to Nelson as any six historic buildings'. I must confess I have two ulterior motives in contributing this article for publication in the Society's Journal.

The first, and more immediate, is to make the qualities and significance of the whole of the Rocks Road seawall, both early and late, much more widely known. This is in order to prevent it being disfigured in an attempt to change the wave regime and beach profile at the eastern end of Tahunanui Beach. The second motive will ultimately be more effective in preserving its forms and effectiveness as a road-protecting structure. It is to set in train the process by which the whole wall, in both its 19th and 20th century vintages, including the short granite section now isolated on Wakefield Quay, becomes recognised as a heritage structure in both the New Zealand Historic Places Trust and City Council lists.

Despite my urgings in 1977, the Rocks Road seawall still has no heritage recognition, though its post and chain fence has an NZHPT Classification I and an NCC Group A ranking.